Angel Star Photography Loc: Tacoma, WA

Several weeks ago I was out in my yard attempting capture shots of a couple of beautiful white moths in flight. I had a Sigma 150-600mm C on a Canon 5D4. Standing at one side of the yard I focused on the bushes and moths while they were flying but for some reason they always wanted to fly towards me. My camera would track for a bit and then quit tracking. I missed a few good shots. Checking out the focusing, everything seemed to work as it should. I did some tests and found that the set up worked well when the target was at the other side of the yard. As I stepped closer, I lost the AF tracking. After several attempts I decided that perhaps I was breaching the minimum focus distance line and changed the lens out for my 70-200mm but it just didn't have the reach I needed to keep from chasing the moths away. I had resigned myself to not ever getting the shot I wanted until today when I was watching Tim Grey on Photo Gear Weekly. Today's talk was on a little switch on some lenses known as the AF Range Limiter. For some reason I thought this was some new feature until he began talking about it and then the moment came---a head-slapping "duh!". I checked my Sigma lens and it was indeed set to 10m-infinity---the setting I have always used when shooting birds in flight. Looking at my yard again, the point where tracking seemed to get lost was around thirty feet. Had I really put some thought into it at the time, I would have realized that no way was thirty feet the minimum focus distance of this lens. Perhaps I was going too deep as I do recall considering the use of extension tubes to reduce the minimum focus distance. Just one of those moments and now I can't help but laugh at myself for trying to make such a big problem out of such a simple but forgotten switch. Yet, experimenting with extension tubes may be an interesting learning experience.

pithydoug Loc: Catskill Mountains, NY

Now you going to make me look at my 5dIII - Thanks.

JD750 Loc: SoCal

Thank you for that informative post.

Moths in fight with tele lens is quite a challenge. Would you care to post some of the successful attempts? I would love to see them.

FYI - Most macro lenses have a switch to limit focus distance. Sometimes it does not matter much but there are times it does matter. On my Olympus 60mm Macro lens, if the Focus Range knob is set incorrectly it will "hunt" for focus whereas when the focus range knob is set properly it will find focus quickly.

Angel Star Photography Loc: Tacoma, WA

I will be glad to post some successful attempts when I make the effort again.

Moths in flight with a tele are definitely a challenge and part of the reason I chose to do so---practicing and honing my skills. Trying to photograph Swifts in flight have also been quite the challenge. I hope to achieve success on both and will be glad to post on this forum when it happens.

47greyfox Loc: on the edge of the Colorado front range

I had a similar situation a number of years ago, tho the details escape me. Since then, after any kind of shoot, I return the lens and body used to the same setup. I suppose it may have cost me a few quick grab and shoot shots over time, but when I grab a camera, I always know the configuration starting point.

AzPicLady Loc: Behind the camera!

I've never heard of this switch before. It's on the lens, right? And not on the camera? I do have a camera menu setting that stops the lens from hunting and allows me to find focus manually.

Angel Star Photography Loc: Tacoma, WA

Hi AzPicLady,

Yes, this switch is on the lens. On the Sigma 150-600mm lens, it has three positions (Full, 10m-infinity, and 2.6-10m). This sets the range between which the lens will focus which helps increase the speed to obtain focus lock and reduces hunting.

tom hughes Loc: Phila Pa

Do you use back button focusing? Works best on moving subjects.

Angel Star Photography Loc: Tacoma, WA

I certainly do, Tom! Ever since I discovered back button focusing, I haven't gone back. I love it for moving subjects and stills when recomposing on a specific subject. The one item that I am now on the fence about is whether to use AI Focus or AI Servo. I was using AI Servo for a while but later when watching Roman Kurywczak shoot birds in flight, I noticed that he talked about achieving focus lock as the subject came into view and following through. You could hear the beep of the focus lock and then he began shooting in burst mode. It seems to me that he was using AI Focus as AI Servo does not give the focus lock confirmation beep. We'll see how well it works.